Process of producing and distilling aqueous sulphuric acid solutions of secondary and tertiary alcohols



Patented Apr. 18, 1933 UNITED STATES BENJAMIN T. BROOKS, OF GREENWICH,CONNECTICUT, ASSIGNOR, BY MESNEASSIGN- MEN-TS, TO STANDARD ALCOHOLCOMPANY, OF WILMINGTON, DELAWARE, A COR- lPOBATION OF DELAWARE TMCESS 0FPRODUCING AND DISTILLING .AQUEOUS SULPHUIRIC ACID SOLUTIONS 0F SECONDARYAND TERTIARY ALCOHOLS Application led June 30,

This invention relates to the production and distillation of aqueoussulphuric aci solutions of secondary and tertiary alcohols.

'lhe secondary and tertiary alkyl sulphates are commerciallymanufactured by the treatment with aqueous sulphuric acid of olefinesderived from the cracking of hydrocarbon substances, such as mineraloils. The alkyl sulphates so formed are ordinarily diluted and distilledfor the production of the corresponding alcohols. My invention isparticularly applicable to the processes of dilution and distillation.

At the present time such distillations are ordinarily carried inapparatus lined with lead, the distillation being carried to the eX-tent of driving overhead in lvapor form the major part of the alcoholWhile leaving a liquid residue in the still consisting of aqueoussulphuric acid. l have discovered, how-4 ever, that where thedistillation is carried out in this manner, or in apparatus lined withmetal generally, the maximum yield of alcohol is not obtained, due tothe formation of p large proportions of oleine by the decomposition ofthe alcohol or alkyl sulphate. These losses may, however, as have found,be materially inhibited or reduced by carrying out the distillationwhile retaining the liquid by surfaces of a vitreous character. Whereasin the prior art the liquid is retained by metal surfaces and especiallyby lead, the retaining metal surfaces appears to exert a catalyticinfluence which promotes the degradation of the alcohol to the less desirable products hereinbefore mentioned.

The term vitreous, as herein employed, includes vitreed earihenvvarebricks, such as acid proof bricks which may be properly bonded by acidresisting cement to form a continuous interior surface, stoneware andlass. f I

It is of further advantage to heat the liquid undergoing distillation bythe direct introduction of steam into the liquid to be distilled. Afurther improvement in percentage of alcohol recovered and in quality ofthe alcohol obtained is effected by carrying out the fractionaldistillation or separation of the alcohol from the mixture by the usesections to prevent 1931. Serial N0. 547,896.

of a stripping column in contradistinction d to a batch distillation.rlhis embodiment of the'invention will be illustrated by reference tothe drawings, in which,

Fig. l is a side elevation with parts in section of4 apparatus in whichthe invention may be carri-ed into eii'ect.

Fig. 2 is a top view of a part of the construction shown in Fig. l.

Fig. 3 is a detailed vertical section through part of the constructionshown in Fig. 1, and

Fig. 4 is a sideelevation of the column shown in Fig. 1,showing inaddition the mode of strapping the sections of the column together.

Referring to Fig. 1, the mixture, containing 4a secondary or tertiaryalcohol and aqueous sulphuric acid, may be introduced, through pipe l,controlled by vvalve 2, to the stripping column 3. As hereinbeforestated, the surfaces of the stripping column in contact with the liquidcontents thereof are constructed of vitreous materials; and in thereferred embodiment of my invention illustrated, the column 3 isconstructed of glass. The column comprises the vapor dome 4,-thecylindrical sections 5, 6, 7 8 and 9, and the connected base l0. rlhecolumn is provided with horizontal partitions crl plates which span thesame and which carry a liquid layer or pool, but in this case thepartitions are constituted by the horizontal glass disks yl0, 11, 12, 13and 14, intermediate the cylindrical sections and properly gasketed tothe said. leakage from the col carries an overiow pipe, such Eachpartition which projects above the suras 20, (Fig. l)

face of the partition and thereby operates to predetermine the level ofthe pool of liquid v accumulated on the surface of the partition.

The liquid introduced through the pipe i passes downwardly from plate toplate and is finally withdrawn from the base af the column by meansofthe overiow 2 1 and the connected educt 22, controlled by the valve23. The column is heated adjacent the base by the direct introduction ofsteam through the pipe 24, controlled by the valve 25. The steamoperates to heat the liquid in the base of the column and in additionthe pool of liquid on the upper surface of the partition 14. Each upwardsection of the column is in turn heated by vapors evolved from thesection beneath, and for this purpose each partition 10 to 14 inclusivecarries some appropriate means for distributing ascending vaporsthroughout the body of the pool of liquid retained on the upper surfaceof the partition. Ordinarily, bell-caps of vitreous material may beemployed, although l nd perfora-v tions in the partition to be suitablefor this purpose, and are, of course, simpler and easier to fabricate.Alcohol vapors are taken off overhead Jfrom the top of the columnthrough the pipe 30 wherein the same are condensed, the resultingalcoholic condensate being withdrawn from the system throu h the pipe32, controlled by the valve '33. the mixture of alcohol and sulphuricacid cascades downwardly through the column from plate to plate, itbecomes progressively impoverished in alcohol. lt will be seen,therefore, that the space between any two adjacent partitions 10 to 14inclusive defines a zone containing liquid and vapor, and that thesezones are at progressively higher temperatures as the base of the columnis approached.

q`Where the alkyl sulphate treated is readily hydrolyzed, it is suhcientto dilute the same with water and feed the mixture so producedimmediately into the stripping column. This is the case, for example,with tertiary butyl sulphate which may be diluted with about one volumeof water and supplied immediately to the column through the pipe 1.There are other alkyl sulphates lwhich do not hydrolyze so readily andwhich for op-I timum yields should be diluted and warmed for a suitableperiod prior to the introduction of the mixture to the stripping column.Secondary butyl sulphate is an example of the latter type. ln such acase the alkyl suly phate is diluted with a suitable quantity of water,say for example `from one to three volumes, and introduced to the pipe40, controlled by the valve 41 to the digesting or hydrolyzing chamber42. This ma consistl of a receptacle" 43 which may be ot acid resistantmetal, although it is preferably of vitreous material, heated by meansof the steam coil 44, and preferably provided with a baille such as 45.The time and tempera-ture to which the mixture is subjected in thehydrolyzing vessel 42 should be suficient to effect the substantiallycomplete hydrolysis of the alkyl sulphate, thereby producing. therefroma mixture consisting predominantly or exclusively of alcohol andsulphuric acid. ln the case of secondary butyl alkyl sulphate, l havefound that a temperature of between and 80 C. and a time of aboutone-half hour is sulticient for this purpose. rllhe temperature should,in any event, be below the boiling point of the alcohol to be produced.

In Fig. 2, I have shown a top view of the stripping column 43 with thedome 4 ref moved.` This illustrates the general arrangement of vaporoutlets 5() and overflow pipes 51. The sections of the column arestrapped together by means of the annular metal flange 52, connectedtogether by means f the stay-bolts 53 of which a number are em-n ployed,passing through' the various holes 54 provided for that purpose in therings 52 and 55.

The internal construction of the column 3 is further shown in detailedsection in Fig. 3, from which it will be noted that the ring 52 bears onthe dome 4 of the column by the projecting integral annular nshoulder60. A resilient gasket 6l is provided intermediate .the shoulder 60 andthe ring 52. Resilient dimensions ot the sections composing the' columnmay he varied over wide limits and the dimensions of the hydrolyzingvessel 42 may be suitably modified in view ot the amount and characterof the alkyl sulphate supplied thereto. lt is my intention that theinvention be limited only by the following claims or their equivalentswherein l have endeavored to claim broadly all inherent novelty.

l claim:

1. Process of selectivly distilling a secondary or tertiary alcohol froma solution containing such an alcohol and aqueous sulphuric acid, whichcomprises distilling the solution while retaining the same by surfacesof a vitreous character and while holding said solution substantiallyexclusively in contact with surfaces of a vitreous character.

2. Process of separating a secondary or tertiary alcohol from a solutioncontaining such an alcohol and aqueous sulphuric acid, which comprisesdistilling the solution while retaining the same by surfaces of avitreous character and while holding said solution substantiallyexclusively in contact with surfaces of a vitreous character, andmaintaining the distillation by the direct inject-ion of steam into 'thesaid liquid.

3. Process of separating a secondary or tertiary alcohol trom a solutioncontaining such an alcohol and aqueous sulphuric acid, which comprisesintroducing the alcohol sulphuric acid mixture into the upper part of astripping column, heating the contents in the lower part of said column,continuously removing alcohol vapor from the upper part of aqueoussulphuric said column,

sulphate, which comprises diluting said alkyl sulphate with water,holding the diluted l sulphate at a temperature in excess of C. andbelow the bolingfoint of the corresponding alcohol, thereby orming analcohol sul huric acid mixture, introducing the alcoho sul huric acidmixture into the upper part o a stripping column, heating the contentsin the lower part of said column, continuously removing alcohol vaporthe upper part of said column, continuously removing sulphuric acid fromthe base of said column, the surfaces of said column in contact with theliquid contents thereof being of vitreous materials. v

6. Process according to claim 5, in which the contents in the lower partof said stripping-column are heated by the direct introduction of steam.

acid while retaining said zones by sur and while holding said solutionsubstantially exclusivel vitreous c aracter.

10. Process according the heat is supplied by the. direct introductionof steam.

BENJAMIN T. BROOKS.

the liquid contents of from Y 7. Process of separating a secondary ortertiary alcohol from a mixture containing the said alcohol and aqueoussulphuric acid,

sulphuric which comprises maintaining a system including incounter-current .communication a vertical series of zones containingliquid supplying fresh alcohol sulphuric acid mixture to the upper partof said senes, supplying 4heat to the lower part said series,continuously removing alco vapor, and continuously removing aqueous acidwhile retaining the h uid contents of the said zones by surfaces o avitreous character and while holding said solution substantiallyexclusively in contact with surfaces ofva vitreous character.

8. Process according to claim 7 whichv the heat 1s supplied by thedirect introduci sulphate, which comprises v taining 9. Process ofobtaining a secondary or tertiary alcohol from the co ndin alkyldiluting sai alkyl sul hate with water, holding and'below the point ofthe correspending alcohol, there y forming an alcohol aqueous sulphuricacid mixture, main- 'a system comprising including in counter-currentcommunication a vertical s'eries of zones containing liquid and vapor,supplying the sald alcohol sul huric acid to the upper part of saiseries, supplymg heat to t e lower apart of said series, conhnuouslyremoving cohol vapor, and continuously removing aqueous sulphuric hol iin contact with surfaces of a" faces of 'avitreous character to claim s,iawhich a the dilutedl al- I, sulphate at a temperature in excess of 50

